How to lock special character in my MacPro keyboard??

My guess is that by "lock" you mean "bind". Many special characters are available by typing character keys on your keyboard while holding the Option key, or the Option and Shift keys together. I've attached pictures indicating which characters can be found where using this method.

characters available by holding only the Option key

characters available by holding both Option and Shift

Note: some or all of these character may be rearranged on a keyboard that is not using the standard U.S. QWERTY keyboard layout. For example, ¥ and Á are both on the "y" key regardless of where the "y" key is located on your keyboard

For special characters not available in this manner, you might be able to use text expansion to automatically replace a certain string of characters with the special character you want. If this doesn't work, you'll likely have to explore third party software such as BetterTouchTool, or Karabiner-Elements.

Please explain what you mean by "lock"?

To make special characters, here is some info:

macOS Sierra: Use emoji and symbols